Topic: CB Front Disc Brakes

[L5wolvesf]

The following is in regard to my Wards CB550 project. http://forums.sohc4.net/index.php/topic,180747.0.html

I’ll try to make this semi-long story short. I ran across a CB200 at wrecking yard and noticed the front had a disc brake. Up till now I had not considered the brakes on my project, a front disc seems like it would be a good idea. However, the Wards bikes did not have a disc brake option and I am not aware of anyone who has done something like that. Since a good portion of the project will be Honda CB an upgrade to a CB front disc would fit in the scheme of things.

In doing a very lil bit o research it seems like CB 350 – 750 share some brake components – is that correct? That seems like the 750 would likely need a bigger front brake than a 350.

If not, do any of the CBs share common components?

Thank you

[MauiK3]

Look for parts diagrams and compare part numbers, that should tell you what you are looking for.

[bryanj]

Basically NO
350, 400, 500 four and twin, 550 four all have same caliper and mount
350 and 400 same disc
500 four and twin plus 550 same disc
750 has two different calipers during years but same disc
Twin cam750 and sohc F2/3 totally different

[carnivorous chicken]

And the CB200 (IIRC) had a cable-operated disc.

[Bodi]

The 350 twin models with discs plus all years of the 350 Four and the 400-F (not the 90's onward CB400 SF) - all front disk brake parts are the same.
What? Honda made motorcycles with cable operated disc brakes??
Anyway, measure the fork tube diameter and spacing. If any of the fours have close or same specs, putting those legs and the matching wheel on will be a lot easier than modifying drum brake lowers to mount a disc. Welding stuff onto the unknown alloy is no joke (and your life is on the line if they come off) plus doing it without distorting the tube - not simple. There are still 350 twin parts in boneyards, parts for fours are getting rare.

[RAFster122s]

Yeah CB200 was cable operated and with age they often became sticky/problematic from what I have read about them…

[robvangulik]

Correct, the brake looks almost the same, the lack of master cylinder on the bars betrays it
This is the bike I started my biking career with, and it really didn't brake bad too!

[L5wolvesf]

XLNT info so far guys – much appreciated

My thought is to swap the whole Honda wheel and brake assembly on to the Wards forks. That also solves any speedo drive differences. Initial measurements look like the swap is possible.

The axle might be where I have to get creative with spacers or some way of adapting one to the other. The Wards axle is either 12 or 13mm.

The Wards fork leg diameter is 44.5mm. What is the fork diameter on the 500 / 550 bikes?

I would prefer a weld free solution.

[carnivorous chicken]

Fork tube diameter on 550s is 35mm (again, IIRC).

[Don R]

 Keeping the wards forks leaves the problem of adapting the caliper mount to the drum brake forks. We're measuring the chrome tube that goes into the triple trees. It's rarely as easy as it sounds. Adapting the honda triple trees with all balls bearings might be easier but every swap comes with trade-offs.

[L5wolvesf]

Keeping the wards forks leaves the problem of adapting the caliper mount to the drum brake forks. We're measuring the chrome tube that goes into the triple trees. It's rarely as easy as it sounds. Adapting the honda triple trees with all balls bearings might be easier but every swap comes with trade-offs.

Is that measured where the fork tube enters lower triple tree?

[L5wolvesf]

I have attached a pic of the Wards fork where the fender attaches. The pic is looking down on the 2 mounting bosses with the fender (brown “patina”) on the upper left side of the pic.

I think I can attach the CB550 caliper bracket to that by making a plate that adapts the bracket to the fender mount. I’ll need to get a CB550 caliper bracket in hand to see how it actually fits.